Akka dispatcher inherritance

Question

I'm working with Akka and we are still getting to get to know each other.

My scenario is : I have chosen a non-default dispatcher for a supervisor (parent) actor who's role is to manage (supervise) and create child actors to do the work.

Question : Does the child actors inherit the parent's actor?

I am aware that you can explicitly specify a different dispatcher for child actors from parent actors given specifying in the configuration.

akka.actor.deployment {
  /my-parent-actor {
    dispatcher = dispatcher-for-parent
  }

  "/my-parent-actor/*" {
    dispatcher = dispatcher-for-children
  }
}

My question is about if you specify the parent actor dispatcher, without explicitly specifying a dispatcher for the children actors, is there inheritance to the children of the parent's actor.

Answer 1

From what I've seen, the child will not inherit the supervisor of the parent by default. I couldn't find this explicitly in the docs anywhere, so I wrote a quick piece of code to verify my initial assumption:

import com.typesafe.config.ConfigFactory
import akka.actor._

object DispatcherTest extends App{

  val conf = ConfigFactory.parseString("""
      {
          my-custom-dispatcher {
            executor = "thread-pool-executor"
            type = PinnedDispatcher         
          }
      }  
  """)

  val system = ActorSystem("test", conf)
  val supervisor = system.actorOf(Props[MySupervisor].withDispatcher("my-custom-dispatcher"))

}

class MySupervisor extends Actor{
  println(s"I am the supervisor, my dispatcher is: ${context.dispatcher}")
  val child = context.actorOf(Props[MyChild])
  def receive = {
    case _ =>      
  }
}

class MyChild extends Actor{
  println(s"I am the child, my dispatcher is: ${context.dispatcher}")
  def receive = {
    case _ =>
  }
}

If you run this, you will see:

I am the supervisor, my dispatcher is: PinnedDispatcher[my-custom-dispatcher]
I am the child, my dispatcher is: Dispatcher[akka.actor.default-dispatcher]